I would sit down with your parents and explain to them (if you have not already) that while you are not sure about medical school, you are sure (at least now) on some type of grad school.
I would also remind them that your major (neuroscience/cell biology) typically requires some type of grad school. Sometimes you can choose a less costly grad school, and sometimes you can’t.
I think it is amazing that your parents will pay for any undergraduate school (I am assuming they are aware of costs). I would ask them if they will also help pay for grad school…or…will attending a lower cost school leave money available for grad school, etc.
Finances are a personal discussion and you do not owe us an explanation, but I would definitely discuss it with your family and plan for the possibility of grad school.
Good luck- you have a nice list!